The sentence Er kam durch das Dachfenster (He came through the window in the roof) gives the answer, so (A) is the correct answer. He did not get in by opening the front door, so (B) is false. Nor was he able to open the kitchen window; therefore (C) is also false. (D) Seine Frau gab ihm den Schlüssel (His wife gave him the key) is not correct. From the story, it's possible she may have left the key under the doormat, but she forgot to put the note where her husband could find it.